Field of the Invention
The present invention relates to a computer system having a function of determining approach of an aircraft, and to an aircraft.
Description of the Related Art
The landing gear of the aircraft is deployed in approach to an airport landing runway, and supports the landed airframe. If the landing gear is not deployed downward in approaching, a warning is given to the pilot. Thus, it is necessary to determine whether the aircraft is approaching.
As the peripheral technology thereof, a Ground Proximity Warning System (GPWS) disclosed in Japanese Patent Laid-Open No. 2001-033271 (paragraphs [0002] to [0006] and FIG. 1) is known. The Ground Proximity Warning System determines approaching state to the ground surface, based on measurement data by a radio altimeter, an air data computer, and a global positioning system (GPS), three-dimensional topography data, and other data, and then issues a warning.
An index to be used for electrical determination whether the aircraft is approaching is not precisely defined. As an index of the determination, for example, positions of flaps and slats are considerable; however, determination whether the aircraft is approaching or in other flight phases such as takeoff, initial climbing, and descending cannot be made only by the positions of the flaps and slats. Thus, it is necessary to consider flight altitude of the aircraft and other factors.
Using a plurality of altimeters is effective to improve reliability of approach determination using the flight altitude; however, addition of devices directly causes weight increase of the aircraft. If the number of mounted altimeters is reduced, it is possible to easily reduce the weight of the aircraft as compared with a case where the weight to be reduced of the airframe structure is derived from aerodynamic load and reduced.
Accordingly, an object of the present invention is to determine approach of the aircraft while avoiding weight increase of the aircraft and securing reliability of approach determination.